1. Field of the Invention.
The invention relates to detachable pipe couplings used on fluid carrying pipes, particularly but not exclusively water pipes such as are used in irrigation systems, and which are required to be readily capable of being coupled together and subsequently uncoupled.
2. Description of the Prior Art.
Various kinds of such pipe couplings are commercially available. As a rule, these are formed by two coupling elements which may form part of two pipe elements to be connected, one of the coupling elements being a female element which forms a socket and the other a male element having an end portion which can be loosely inserted into the socket formed by the female element, and sealed thereto by a resilient seal, preferably a lipped seal which closes under the pressure of the fluid being carried and allows the axes of the two members to be displaced slightly in relation to one another. The two elements also have attachment means for attaching the two elements together after the male end portion has been fitted into the female element and retaining them axially against the internal pressure of the fluid being carried, the attachment means being of a nature which can be readily actuated manually and generally being a pair of attachment means at positions diametrically opposite to each other. A large variety of such attachment means are commercially available. Such pipe coupling devices allow a limited amount of angular deflection of the axes of the two coupling elements relative to each other, and hence allow relative angular deflection of the axes of any pipe elements to which the coupling elements are fitted. However, although the use of a pair of attachment means at diametrically opposite positions allow limited relative angular movement in a plane perpendicular to a diameter extending between the attachment means, relative angular movement within the plane of that diameter results in an unequal distribution of the forces applied to the attachment means and this can be a serious disadvantage, especially in the case of pipes of large cross section carrying water at the high pressures customarily used.